The small New England college town (Williamstown) where Gifford (English & American Studies/Williams College) lives seems exactly apposite for these insightful reflections on two centuries of rapid change in time and space, in science and technology. Gifford chooses 1798 and 1984 to bracket the interval, the earlier years coinciding with Wordsworth, and Coleridge's Lyrical Ballads, and Malthus' famous essay, while 1984 pays homage to George Orwell. There is an overall sad cast to these essays, a lament that the borders of life are no longer well defined; that we live an edgeless existence dependent on the high-tech paraphernalia that keep us in constant electronic touch, that power our homes in networks that make us another link in a grid of a supercity. In contrast, there is Gilbert White, the 18th-century curate and father of natural history, whom Gifford turns to repeatedly as he examines how perceptions have changed, how space and time boundaries have expanded, how notions of privacy and subjectivity have come into being, while ""average"" man has become a statistical nonentity. Of the senses, vision now reigns supreme and the constant exposure to TV, in contrast to film, runs the risk of transforming all objects of perception from elephants to brine shrimp to a standard 3-by-4-inch size. Our ears, once attuned to books read aloud, to theater and symphony in small spaces, have grown accustomed to amplification and computerization; the narrator's voice now interiorized; Haydn on compact disk. Gifford's rich store of literary criticism and social history serve him well as he elaborates these themes in Thoreau, Emerson, and Poe, and, later, in Marx, Freud, James, and Joyce. His epilogue serves as corrective, however. Our sensibilities have not markedly changed, he admits: There is a Homer that speaks to us, as he did to Gilbert White and Thoreau. Still, for a searching examination of the remarkable differences overlying that shared sensibility, Gifford is an excellent guide.